1. Field of the Invention
This invention relates to pyrrolidonyl oxazoline compounds, and more particularly, to polymerizable pyrrolidonyl 4,5-unsubstituted oxazoline monomers, homopolymers thereof having advantageous complexation and solubilization properties, and copolymers with other monomers.
2. Description of the Prior Art
Polyvinylpyrrolidone (PVP) is a well known synthetic polymer having properties which are suitable for many pharmaceutical, cosmetic, clinical and industrial uses. An important property of PVP is an ability to form complexes with a variety of compounds, such as iodine, phenolic materials, dyes etc.
Other useful properties of PVP include water solubility, adhesion to many substrates, suspending and emulsifying capabilities, relative inertness, ability to form clear brittle films from various solvents, and its non-toxicity.
However, PVP is not without its deficiencies. Some of these include a high glass transition temperature, Tg, of 175.degree. C. and a high melt viscosity, which preclude its use in thermoplastic forming operations; an amorphous structure; non-biodegradability, which prevents complete elimination from the body after intravenous administration; and steric crowding between the pyrrolidone lactam ring and the hydrocarbon backbone of the polymer which limits its complexation with other molecules when dipole-dipole interactions are involved.
Accordingly, it is an object of the present invention to provide new and improved pyrrolidone-containing polymers.
The literature has disclosed two pyrrolidonyl 4,4'-dimethyl substituted oxazoline compounds for use as an intermediates in the synthesis of medicinal drugs [Zoretic, P.A. J. Org. Chem. 45, No. 5, 810-814 (1980) and Zoretic, P.A. J. Org. Chem. 42,No. 19, 3201-3203 (1977)]. However, the presence of the dimethyl substituent group in the oxazoline ring is known to preclude its polymerization into polymeric materials [Levy, A. J. Poly. Sci Part 1-A 6, 57-62 (1968)].
Accordingly, it is another object of this invention to provide polymerizable monomers of pyrrolidonyl oxazolines, and homopolymer and copolymers thereof.
A particular object herein is to provide a polymerizable pyrrolidonyl 4,5-unsubstituted oxazoline monomer and a homopolymer thereof having a lactam ring which is spaced away from the hydrocarbon backbone of the polymer, thus avoiding the steric crowding deficiency of PVP.
Still another object of the invention is to provide pyrrolidonyl oxazoline polymers having two amide moieties per repeat unit to enhance its complexation properties.
Among the other objects herein is to provide advantageous processes for the homopolymerization and copolymerization of the monomer compounds of the invention.